CN103835984A - High-order rotational distortion generator with demountable disturbing rods - Google Patents

Abstract

The invention discloses a detachable spoiler-rod type high-order rotational distortion generator, which belongs to the technical field of impeller machinery. It includes a rotating disk, several spoiler rods, a balance device and a motor. The inner ring of the rotating disk is a boss connected to the driving motor. The balancing device is installed on the middle ring of the rotating disk, and the outer ring of the rotating disk Several threaded holes are provided, and the several spoiler bars are detachably mounted on the threaded holes. The present invention adopts a detachable connection structure between the spoiler rod and the rotating disk, so that high-order rotational distortions with different circumferential ranges and different numbers of disturbance clusters can be produced, and can adapt to various experimental requirements; The disassembled counterweight device is used to adjust the static balance of the distortion generator, so that the distortion generator of the present invention can work at a higher rotational speed.

Description

Detachable spoiler-type high-order rotational distortion generator

technical field

The invention relates to a spoiler-rod type high-order rotational distortion generator, in particular to a detachable spoiler-rod type high-order rotational distortion generator, which belongs to the technical field of impeller machinery.

Background technique

Intake distortion is one of the key factors that induce compressor flow instability, which greatly limits the performance and stable working range of aeroengine compressors. Modern aeronautical gas turbine engines widely adopt twin-shaft or multi-shaft structures. The aeroengines with this structure have the problem of mutual influence between high-pressure and low-pressure compressors, especially the influence on their respective stall boundaries or stability margins. In a multi-shaft aviation gas turbine engine, when the upstream compressor rotates and stalls, the stall mass propagated in the circumferential direction will propagate downstream with the main flow, so that the downstream compressor works under a special inlet flow field, which is called It is the rotation intake distortion.

At present, one of the main technical means to study the influence of rotary intake distortion on compressor stability at home and abroad is to conduct a rotary intake distortion test, and the key to the test is to simulate the rotary intake distortion of the compressor inlet, because it is impossible in the experiment A true rotating stall compressor is placed at the compressor inlet to generate the rotating stall. In order to study the influence of rotating intake distortion on compressor stability, it is necessary to change the rotation speed, strength, circumferential range, and number of disturbance clusters of intake distortion to simulate the real stall cluster structure of the upstream compressor.

There are two commonly used rotary intake distortion simulation devices at this stage: (1) Rotary distortion net. It is composed of a bracket, a supporting net, a base net and a sticking net. The sticking net has different specifications and shapes, and the distortion intensity and the range of the distortion zone can be changed. Due to the presence of interference factors such as brackets, the pressure waveform generated by the rotation of the distortion net is relatively messy, and the same waveform cannot be maintained at different speeds, so the influence of the waveform cannot be ruled out during the experiment. The biggest disadvantage of this structure is that the strength is poor and the speed cannot be too high. Once the distortion net disintegrates when it rotates, it will cause a major accident after being sucked into the compressor test piece. Therefore, the rotational distortion net can only be used at low rotational speeds, which greatly limits its application in experiments. (2), spoiler stick simulator. In 2001, Thomas Peters, Thomas Burgener and Leonhard Fottner published the paper "EFFECTS OF ROTATING INLET DISTORTION ON A 5-STAGE HP-COMPRESSOR" at ASME TURBO EXPO 2001, and designed a spoiler-type rotational distortion simulator. It consists of a rotating disk and spoiler rods fixed on it. The spoiler rods cover a range of 120 degrees in the circumferential direction, and the cross-section of each spoiler rod is a square with a side length of 5mm. This kind of rotational distortion simulator can work at high rotational speeds, but since the spoiler rod and the rotating disc are integrally constructed and cannot be disassembled, it can only simulate the rotational distortion of a single cluster with a certain intensity and circumferential range. The square cross-section also disturbs the resulting distortion.

Contents of the invention

The technical problem to be solved by the present invention is to overcome the defects of the prior art and provide a detachable spoiler-type high-order rotational distortion generator capable of simulating the rotational intake distortion of different circumferential ranges, different intensities, and different numbers of disturbance groups .

In order to solve the above technical problems, the present invention provides a detachable spoiler-type high-order rotational distortion generator, which includes a rotating disk, several spoilers, a balance device and a motor. The boss connected to the motor, the balance device is installed on the middle ring of the rotating disk, the outer ring of the rotating disk is provided with several threaded holes, and the several spoiler bars are detachably installed on the threaded holes.

In the detachable spoiler rod-type high-order rotational distortion generator of the present invention, the spoiler rod includes a working section and a connecting section, and the connecting section is provided with threads for connecting threaded holes and positioning bosses.

In the detachable spoiler-rod type high-order rotational distortion generator of the present invention, the cross-section of the working section of the spoiler rod is circular.

In the detachable spoiler type high-order rotational distortion generator of the present invention, the balance device includes a balance slider and a counterweight, and the balance slider is installed in a slide rail distributed along the circumferential direction of the middle ring of the rotating disk, The counterweight is installed on the counterweight threaded hole between the outer side of the slide rail and the outer ring of the rotating disk.

In the detachable spoiler type high-order rotational distortion generator of the present invention, the balance slider includes a first slider and a second slider, the second slider is placed in the slide rail, and the first slider is sleeved and fixed on the second slider.

In the detachable spoiler type high-order rotational distortion generator of the present invention, several weight-reducing holes are provided between the inner ring and the middle ring of the rotating disk.

The detachable spoiler-rod type high-order rotational distortion generator of the present invention also includes a plug detachably installed on the threaded hole of the outer ring of the rotating disk.

In the detachable spoiler rod type high-order rotational distortion generator of the present invention, the structure of the connecting section of the plug and the spoiler rod is the same.

The beneficial effects of the present invention are: (1), the distortion generator of the present invention adopts a detachable connection structure between the spoiler rod and the rotating disk, so that high-order rotational distortions with different circumferential ranges and different numbers of disturbance clusters can be generated, It can adapt to various experimental needs; (2) By changing the thickness of the spoiler rod, the intensity of the rotating intake distortion can be controlled; (3) By setting a detachable counterweight device on the rotating disk to adjust the distortion generator Static balance enables the distortion generator of the present invention to work at a higher rotational speed.

Description of drawings

Fig. 1 is a schematic diagram of the structure of the spoiler rod in the present invention, in which (a) is a top view, and (b) is a main view;

Fig. 2 is the structure diagram of rotating disk in the present invention, among the figure (a) is sectional view, (b) is main view, 1-boss, 2-threaded hole, 3-sliding rail, 4-counterweight threaded hole, 5- lightening hole;

Fig. 3 is plug schematic diagram among the present invention, among the figure (a) is main view, (b) is top view;

Fig. 4 is a schematic diagram of a counterweight in the present invention, among which (a) is a front view, (b) is a top view, and (c) is a left view;

Fig. 5 is a schematic diagram of the first slider in the present invention, in which (a) is a front view, (b) is a top view, and (c) is a left view;

6 is a schematic diagram of the second slider in the present invention, in which (a) is a front view, (b) is a top view, and (c) is a left view;

Fig. 7 is a schematic diagram of changing the distortion sector in the present invention;

Fig. 8 is a schematic diagram of changing the number of distortion perturbation groups in the present invention.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

The detachable spoiler rod type high-order rotational distortion generator of the present invention is composed of a rotating disk, several spoiler rods, a plug, a balance slider, a counterweight and a driving motor.

As shown in Figure 1, the spoiler bar is divided into two sections. The left half in Figure 1(b) is the working section, which generates a low-pressure area after the airflow passes through it. The right half in Figure 1(b) is the connecting section, including the connecting section. threaded holes and positioning bosses. The cross-section of the working section of the spoiler rod is circular, and its diameter is 8mm. Changing the diameter of the working section can change the intensity of the rotating intake distortion.

As shown in Figure 2(a) and Figure 2(b), the rotating disc is used to drive the rotation of the spoiler bar. When designing the rotating disk, the diameter of the rotating disk is determined according to the inner diameter of the compressor inlet pipe, and the thickness of the rotating disk is determined according to the strength requirements. The rotary disk includes an inner ring, a middle ring and an outer ring, wherein the inner ring is a boss 1 for connecting with the motor shaft, and the boss 1 has a keyway and a screw hole for axial fixing. The middle circle of the rotating disk is provided with slide rails 3 distributed along the circumferential direction, and two gaps are symmetrically arranged at the horizontal position of the slide rails 3, which are used to place the balance slider. The balance slider can slide freely along the slide rail 3 and be fixed to realize Fine-tuning of the static balance of the rotating disk; multiple pairs of counterweight threaded holes 4 are provided between the outer side of the slide rail 3 and the outer ring of the rotating disk, which are used to connect and fix the counterweights to achieve rough adjustment of the static balance of the rotating disk. The quantity and specific positions of the balance sliders and counterweights can be adjusted according to actual balance needs. There are several threaded holes 2 on the outer ring of the rotating disc, which are used to connect the spoiler rods. In order to ensure the strength of the rotating disc, a certain distance should be kept between the threaded holes 2 . In order to reduce the weight of the rotating disk, there are a plurality of weight reducing holes 5 between the inner ring and the middle ring of the rotating disk (ie at the center of the rotating disk), and the number of the weight reducing holes can also be increased or decreased according to actual needs. In this embodiment, 49 threaded holes 2 are evenly distributed on the upper half circle of the outer circle of the rotating disk, and 3 threaded holes 2 are evenly distributed on the lower half circle; 4 pairs of counterweight threaded holes 4 are evenly distributed on the lower half circle of the rotating disk; There are 4 lightening holes 5 .

When the threaded hole 2 in the circumferential direction of the outer ring of the rotating disc is not equipped with a spoiler bar, in order to prevent the air flow from leaking from the threaded hole 2, the threaded hole 2 needs to be blocked by a plug. As shown in Figure 3(a) and Figure 3(b), the structure of the connecting section of the plug and the spoiler is the same. When in use, insert the plug into the threaded hole 2 of the outer ring of the rotating disk and then tighten the nut to fix it. Just fill the counterbore for positioning in threaded hole 2.

As shown in Figure 4 (a), Figure 4 (b), and Figure 4 (c), the counterweight is used for rough static balance adjustment, and its upper and lower circular arcs are stuck on the upper and lower slide rails of the rotating disk. Between the outer rings of the discs, use two M6 screws and nuts to fix them on the counterweight threaded holes. The balance slider in the distortion generator of the present invention is used for the fine-tuning of the static balance, and there are two upper and lower pieces, including the first slider, as shown in Figure 5 (a), Figure 5 (b), and Figure 5 (c), and the second Two sliders, as shown in Figure 6(a), Figure 6(b) and Figure 6(c). The second slide block sinks in the slide rail of the middle circle of the rotating disk, and the first slide block is sleeved on the second slide block and can be fixed by tightening with nuts. The distortion generator in this example is designed with a maximum speed of 1500r/min, the speed is low, and the elastic deformation can be ignored. The balance problem belongs to the balance of the rigid rotor, which can be solved by using the force system balance theory. The radial dimension of the rotor is D=540mm, the axial dimension b=30mm, and the diameter-to-width ratio D/b=18. For a rigid rotor with a diameter-to-width ratio D/b≥5, because of its small axial dimension, it can be approximately considered as The mass is distributed in the same rotary plane, as long as the static balance is achieved.

As shown in FIG. 7 , three structures from left to right in the figure can be used to generate distortions in the circumferential range of 180°, 90° and 30° respectively. Take the situation of 180° as an example: when the airflow flows through the spoiler rods at a certain speed, a low-pressure area will be generated behind it; because the distribution of the spoiler rods is very dense, the 49 low-pressure areas generated by the 49 spoiler rods will interact with each other. Blending, finally forming a low-pressure zone covering a range of 180° in the circumferential direction, that is, 180° circumferential distortion. The same is true for 90° and 30°. Using this method, the distortion generator can simulate single cluster distortion in the circumferential range of 0°~180° (with an adjustment accuracy of 3.75°), and generate a corresponding square-wave total pressure distribution at the downstream compressor inlet.

As shown in Figure 8, the four structures from left to right in the figure are the high-order rotation distortions used to generate single, double, quadruple and octal clusters. Due to the sparse distribution of the spoiler rods and the large intervals, the low-pressure areas generated by the airflow passing through each spoiler rod cannot be fully mixed, resulting in multiple low-pressure areas at the inlet of the downstream compressor, that is, high-order rotational distortion.

The intake distortion generated by the present invention belongs to the circumferential intake distortion. It can be used to generate single-cluster distortion in different circumferential ranges, which is manifested as a square-wave distribution of the inlet parameters, and the Fourier expansion of the distribution along the circumferential direction is the sum of the four-order Fourier series of the circumferential coordinates; it can also be used In order to produce circumferential distortion with multiple numbers of perturbation cliques, the Fourier expansion of the inlet parameters along the circumferential direction mainly includes the high-order term of the circumferential coordinates, that is, high-order rotational distortion. The detachable spoiler rod type rotary distortion generator of the present invention can be directly used in the rotary intake distortion test, and the compressor involved is an axial flow compressor; the spoiler rod and the rotating disk are detachably connected through threads , air flow through the spoiler bar will create a low pressure area. The motor drives the rotating disk to generate a pressure waveform in the form of a square wave. By disassembling the spoiler bar, the circumferential range of the rotating intake distortion and the number of disturbance groups can be easily changed. Changing the thickness of the spoiler bar can change the distortion of the rotating intake. Intensity, changing the speed and direction of the motor can change the speed and direction of the intake distortion, which realizes the requirement of simulating various types of rotating intake distortion at the compressor inlet. The rotating disk adjusts the static balance of the distortion generator through the counterweight and the balance slider, so that the distortion generator can work at a higher speed.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, some improvements can be made without departing from the principle of the present invention, and these improvements should also be regarded as the present invention. scope of protection.

Claims (8)

1. a detachable flow-disturbing bar type high-order rotational distortion generator, comprise rotating disc, some flow-disturbing rods, Equilibrator and drive motor, the inner ring of described rotating disc is the boss being connected with drive motor, described Equilibrator is arranged on the centre circle of rotating disc, it is characterized in that: the outer ring of described rotating disc is provided with several tapped holes, described some flow-disturbing rods are arranged on tapped hole with removably.

2. detachable flow-disturbing bar type high-order rotational distortion generator according to claim 1, is characterized in that: described flow-disturbing rod comprises active section and linkage section, and described linkage section is provided with for the screw thread in connecting thread hole and the boss of location.

3. detachable flow-disturbing bar type high-order rotational distortion generator according to claim 2, is characterized in that: the active section cross section of described flow-disturbing rod is for circular.

4. according to the detachable flow-disturbing bar type high-order rotational distortion generator described in claims 1 to 3 any one, it is characterized in that: described Equilibrator comprises balance slide block and balancing weight, described balance slide block is arranged on rotating disc centre circle along in the slide rail circumferentially distributing, and described balancing weight is arranged on the counterweight tapped hole between slide rail outside and the outer ring of rotating disc.

5. detachable flow-disturbing bar type high-order rotational distortion generator according to claim 4, is characterized in that: described balance slide block comprises the first slide block and the second slide block, and the second slide block is placed in slide rail, and the first slide block socket is fixed on the second slide block.

6. according to the detachable flow-disturbing bar type high-order rotational distortion generator described in claims 1 to 3 any one, it is characterized in that: between the inner ring of described rotating disc and centre circle, be provided with several lightening holes.

7. according to the detachable flow-disturbing bar type high-order rotational distortion generator described in claims 1 to 3 any one, it is characterized in that: also comprise with removably and be arranged on the plug on the tapped hole of rotating disc outer ring.

8. detachable flow-disturbing bar type high-order rotational distortion generator according to claim 7, is characterized in that: described plug is identical with the linkage segment structure of flow-disturbing rod.

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